Refrigerating apparatus of the compression type



Sept. 16, 1941. R, lNTzE 2,256,201

REFRIGERATING APPARATUS OF THE COMPRESSION TYPE 55 15 74 E i a 2 9%. f; 36 J3 g 5; 38 ii 40 1] U, Pr U ll main M W W B Patented Sept. 16, 1941 UNITED. STATES PATENT OFFICE REFRIGERATING APPABATUS'OF THE COM- PRESSION TYPE Rudolf Hintza Berlin-Charlottenburg, Germany, assignor to Siemen's-Schuckertwerke Aktien-' gesellschaft, Berlin-Siemensstadt, Germany, a

corporation of Germany Application February 24, 1938, Serial No. 192,287 In Germany February 26,1937

13 Claims.

ever, the fact that a great number of parts cona relatively high level, although a refrigerator placed on the market at more moderate cost would answer a perennial and extensive demand.

An object of my invention is. to provide a refrigerating apparatus of the compression type in which the compressor has a simple, economical and reliable construction which allows simplifying the manufacture and reducing the cost of manufacture as compared with the compressors heretofore employed in refrigerating apparatus. Another object of the invention is to reduce in a compressor of the type here concerned those elements which in order to ensure a satisfactory operation require an accurate machining to gauge.

Still another object is to .combine an. electric motor and a rotary compressor in such a way that the compressor when in operation also produces an effective lubrication of the motor.

An object also is to produce the compressive other improvements as will become apparent from the following.

According to the invention, a self-priming centrifugal pump utilizing the action of a revolving liquid ring is made use 'of for drawing in. the refrigerant from the evaporator and for compressing the same. The individual parts of such a compressor, hereinafter referred to as liquid-ring compressor, need not in the course of manufacture be accurately machined to gauge. The compressor further presents the great advantage that it ensures a starting under no load of its driving motor without the necessity of employing auxiliary control means. For this reason the liquid-ring compressor may be attached directly to the driving motor. In practice the driving motor is preferably connected directly to the vane wheel of the liquid ring compressor and the container in which the liquid ring, operates is rotatably mounted so that it is entrained by the vane wheel owing to ,the friction of the liquid. Further features of the invention will become apparent from the following description of the embodiments illustrated in the drawings.

Fig. 1 is a vertical sectional-view of a motorcompressor set according to the invention enclosed in a housing which is under pressure of evaporation. Fig. 2 shows a horizontal sectional view of'the liquid-ring compressor of Fig. 1. Fig. 3 is a vertical sectional'view of a modified form of the invention in which the housing containing the motor-compressor set is under pressure of condensation. Fig. 4 shows another modification of the invention in which the liquid ring comeffect by means of a liquid pumping medium which at the same time is used as a lubricant.

A further object of my invention is to construct a compressor unit, in particular for refrigerating systems, which while employing a liquid pumping medium ensures by simple and effective means a. separation of this liquid from the fluid to be compressed.

An object also is to provide for the starting of no'load condition without usingfadditional pressure relief valves or similar auxiliary mecha nisms.

Further objects concern a favorable structural combination of a separate lubrication pump with a compressor unit, in particular, with a rotary element of a so-called liquid-ring compressor, and

I the electro-motor' of a refrigerating system under pressor has only one chamber. zontal sectional view of the liquid ring compressor of Fig. 4. Fig.6 shows a domestic refrigerator in. diagrammatic form equipped with the compressor shown in Figs. 4 and 5. I

Referring to Fig. 1, [denotes thestationary housing 'of the compressor. The upper part of the housing contains the electric motor, the compressor being arranged in the lower part. The bottom portion of housing I; forms an-oil sump. The stator 2 of the electric motor is mounted in a support 3 which separates the chamber 4 forthe reception of the compressor from the upper part containing the electric motor. The' rotor i Y of the electric motor'is mounted on a shaft 6' arranged in the support 3. To the lower end of v the shaft is secured the impeller 24 of the liquid- .ring compressor having the shape of a vane Fig. 5 is a horinotes the container for the liquid. ring. The container 8 is rotatably mounted on the shaft 9 firmly secured to the bottom III of the housing I. and is provided with a hub II in which are arranged passages l2. The vane wheel 24 has eight compartments l3 or pumping chambers from which extend channels" in the upward direcand a pressure duct I6 respectively, arranged in the lower part of the supporting member. denotes a check valve inserted in the pressure duct for controlling the flow of the refrigerant.

Conduits l8, l9 and 20 join the liquid-ring compressor .with a condenser 2|, a control valve 22 and an evaporator 23 so as to form a refrigerating circulation system. l

When the apparatus is at rest the housing is filled up with oil to the level hl. When starting the electric motor the pumping chambers I3 of the vane wheel 24 are not yet closed by the the liquid ring closes the chambers I 3 completely,

the suction conduit l8 extending from thee-vaporator is directly connected to the suction channel l arranged in the supporting member 3.

tion. When the compressor is in operation these channels l4 cooperate with a suction duct l5 The liquefied refrigerant is supplied in' this Y case to the housing I of the compressor through the-pressure duct-J6 and the check valve ll so that the housing is under pressure of condensation. The conduit leading to the condenser 2| is connected to the housing I. Here the housing I acts as an oil separator, since the vaporous refrigerant containing oil forced out through the pressure channel IE will be separated from V the oil when impinged upon the wall of the housing. The oil flows along the walls of the casing I in the downward direction, whereas the vapors flow into the condenser through the conduit 20. Dichlormethane or other refrigerants having-a -lowpressure of. condensation may beemployed as refrigerants in the refrigerating apparatus cumstances, also a multi-stage' arrangement of according to ,the invention. Under certain cirliquid ring compressors may also be employed.

' The motor-compressor setin'Figs.-4 to 6 is en- 7 closed in a housing consisting of. a pot-shaped 'tank 3| and a cover 32. To the cover is secured the stator 33-of the electric motor by means of its support 34. The rotor 35 of the electric motor is mounted on.a hollowshaft 35-rotatably mounted in an upper bearing 31 secured to the cover 32,

whereupon the motor is under full load: The

rotating liquid ring now has the shapeindicated: in Figs. 1 and 2 by 25, its, inner surface bein The refrigerantdrawn into designated by 26. the'chamber 4 through the conduit l8 now" passes through the conduit l9 and the channel l5 into that chamber |3' of the vane wheel,'the channel I of which just passes the channel. I5 and tem-' porarily communicates with the channel l5. This chamber I3 is that'shown in position I at the off the communication of its .passage II with right-hand side of Fig. 2. Upon rotation through an angle of :18 0, this "chamber, while cutting channel l5, passes through positions II, III and IV into. position V wherein passage ll communicates with conduit 2ll.through check] valve Owingto the eccentricity of liquid ring.25 with respect to wheel 24, the refrigerant enclosed in chamber |3,"when it leaves position I, 'is in.-

creasing'ly compressed until position V isreached and in a lower bearing'38 forming part of the support 34. The lower part 39, of the hollow shaft carries-the impeller 40 of the'liquid-ring compressor. .To the impeller 40 are secured two I 'plates' 42, 3 by means. of rivets 4|. denotes the container in which is set up the liquid ring upon the rotation of rotor 40. The container l5 v is rotatably mounted on'a bearing 46 securedto thesupport 34 of the stator by means of arms 41. The bearing 46 has a stationary pinion 48 in the form of a hollow sl. -.ft and is designed as an oil pump according-to my copending application; Serial No. 160,011, filed August :20, 1937.

. The oil filling the lower po'rtionof the hous I ing-3|. passes during the operation through the inlet channels 49, the thread 59 of the oil pump and the channels 5| into theinner bore 52 of the stationary part of the pump and. then into and the compressed refrigerant is forcedthrough thechann el l4 and the check valve into the pressure-conduitill Chamber 13, while passing from position v throu h positions VI, VII, VIII and 1X, is subjected by the liquid ring to an iricreasing suction,'so that as soon as position I is-re'ached or approached and the chamber again communicates with channel I5, another amount of refrigerant is drawn in. The eight other chambers l3 act accordingly.

The compressedrefrigerant forced through valve- II passes into the condenser 2| and, when liquefied, through control var-e 22 into' the"evapo rator 23 whence it is drawn into thechamber 4"'of. the compressor through the suction conduit I8. During the operation of the compressor; the oil in the bottom portion of t the. housing is ifitensively agitated by the rotary container 8.so that'an-effective" lubrication is b ei Fig.3 shows another embodiment of the .in-. vention in which the compressor housing is under. pressure of condensation, the parts correspond ing to' those shown in Fig, '1 being deno'ted or; the same reference numerals. In this embodiment the conduit 53 which extends through the upper cover 32 of thehousing 3| as indicated at.54.

The lubricant is forced through a cooler 55 arranged exteriorly of the housing 3| and then" passes'into the lubrication channels 56; 51 of the hollow'shaft 36- and returns to the lowerpart of the housing 3| through outlet openings 59.-

At standstill the housing 3| -is'filled with oil up to the level hi.

may enter the container 45 through the lower inlet openings 59. In operation the oil'is so adjustedowing to the centrifugal force that "itfills up the portion -ofthe liquid container 4 5asfl1nd catedat the right-hand side of the romaine- The oil level in the housing3|- thenattains the'.

height hz. The'liquid ring is supplied withircsh. oilgthrough the openings 59 owing to the pumping action brought about during the rotation of the container. The excessive oil flowsback into the housing 3] through the upper opening 6|.-

The suction and pressure effect producedin operation by the extension 44 connected to the impeller" and cooperating with the liquid ring in the container 45., Y The refrigerant is drawn in fromtheevaporator through the conduit 62 and masses thrc ,:-;h the hollow shaft '38 intoth'e duct When starting the electric motor the' liquid-ring container 45 is entraineri A Y the rotation of "the impeller 40 so that the o 63 extending through the impeller (Fig. and then into the suction chamber formed of' the liquid ring, the two plates 42, ll and the rotor 40, whence it is forced through a pressure valve 4 into the pressure duct 65 which communicates with the inner space of the housing 3|. The compressed refrigerant passes then from the interior ofthe housing to the condenser through a conduit 66 connected to the cover 32.

In the embodiment shown in Fig. 6, the housing 3| of the motor-compressor set is mounted on top of the refrigerator cabinet and is supported by springs 61. 68 denotes the evaporator of the refrigerating apparatus. 69 is an aircooled condenser from which the liquefied refrigerant is supplied through a conduit II to a container II in which operates a float-controlled valve 12. From the container I L the liquid is supplied to the evaporator through a conduit 13. 14 and 15 denote the oil circulation conduits extending to theair cooler 55 for the lubricant.-

The set is cooled by a fan 'll driven by an electric motor I6. This fan supplies cooling air in the direction of the arrow for dissipating the heat of the condenser and the cooler 55. The cooling air enters the hood I9 enclosing the apparatus through an opening ll in the rear of the refrigerator and escapes through front outlets 80.

- The oil contained in the apparatus as shown in the embodiment according to Figs. 4 to 6 serves various purposes. First, it forms the liquid ring necessary for the operation of the compressor, secondly it lubricates all rotating parts and bearings, and finally its circulation is utilized for dissipating to the atmosphere the heat developed in the compressor and the electric motor. In a frigerating systems, having a sealed housing forming an oil sump, a limited quantity of oil disposed in said sump, a stationary member in said housing having a suction duct and a com-. pression duct, a rotary impeller arranged in said housing, a container eccentrically surrounding said impeller and forming a pumping chamber together with said impeller, said suction duct and said compression duct being arranged to sequentially communicate with said chamber when said impeller is in operation, said container having ducts communicating with said sump to effect the formation of an annular oil body in said container for compressively acting on said chamber when said impeller is in operation,- an electric motor disposed in said housing and connected with said impeller, and means for causing the oil to lubricate said motor when said impeller is in operation.

2. A compressor unit for refrigeratingapparatus, having a sealed housing forming an oil sump, a limited quantity of oil disposed in said sump, a stationary member in said housing having a suction duct and a compression duct, said suction duct communicating with the interior of said housing, a rotary impeller arranged in said tion duct and said compressionduct being arranged to sequentially communicate with said chamber when said impeller is in operation, said container having ducts communicating with said sump to effect the formation of an annular oil body in said container for compressively acting on said chamber when said impeller is in operation, an electric motor disposed in said housing and connected with said impeller, a pressure consump, a limited quantity of oil disposed in said sump, a.stationary member in said housing having a suction duct and a compression duct, said compression duct having its discharge end communicating with the interior of said housing, a rotary impeller arranged in saidhousing, a container eccentrically surrounding said impeller and forming a pumping chamber together with said impeller, said suction duct and said compression duct being arranged to sequentially communicate with said chamber when said impeller is in operation, said container having ducts communicating with said sump to effect the formation of an annular oil body in said container for compressively acting on said chamber when said impeller 'is in operation, an electric motor disposed in said housing and connected with said impeller, means associated with one of the aforesaid movable parts of the compressor unit for causing oil from said sump to lubricate said motor, a suction conduit connected with said suc- 'tion duct and leading directly out of said-housing, and a pressure conduit connected with said housing and having its opening above the level of said oil, whereby said unit'also forms an oil separator. I

4. A compressor unit for refrigerating. apparatus, having a sealed housing forming a sump,

a limited quantity of pumping liquid disposed insaid sump, a stationary member in said housing having a suction duct and a compression duct, said compression duct having its discharge end communicating with the interior of said housing, a rotary impeller arranged in said housing, a container eccentrically surrounding said impeller and forming a pumping chamber to-, gether with said impeller, said suction duct and said compression duct being arranged to sequentially communicate with said chamber when said impeller is in operation, said container aving ducts and communicating with said sump to effect the formation of a centrifugated liquid ring in said container compressively acting on said chamber when said impeller is in operation, a suction conduit connected with said suction duct and leading directly out of said housing, and a pressure conduit communicating with the interior of said housing and having its opening above said liquid medium.

5. A compressor unit ing, an oil sump, a limited quantity of oil disposed in said sump, a stationary member in said housing having a suction duct and a compression P duct, said suction duct communicating with the for a refrigerating circulation system, having a sealed housing formtain the interior of said housing under low. presranged in said housing, a rotatable container ec- I centrically surrounding said impeller and forming a pumping chamber together with said impeller, said suction duct'and' said compression duct being arrange to sequentially communicate with said chamber when said impeller is in operation, said container having ducts communicatingtwith said sump to effect the-formation of an annular oilbody in said container for compressively acting tion, an electric motor disposed in said housing and connected with said impeller,,means associated ,with one of the aforesaid movable parts of the compressor unit for causing-oil. from said sump to lubricate said motor, a pressure conduit connected with said compression duct and leading out of said housing, and a suction conduit connected with said housing so as to mainsure.

.10 on said chamber when said impeller is in opera- I 2,256,201 interior of said housing, a rotary impeller arliaving a suction duct and a compression duct, an impeller mounted on said shaft, and a rotary container eccentrically surrounding said impeller so as to form a pumping chamber together with said impeller, said suction duct and said compression duct being arrangedto sequentially communicate with said chamber when said impeller is in operation, said container having ducts communicating with said sump to effect the formation of an oil ring compressively acting on said chamber when said impeller isin operation, a rotary lubrication pump arranged in said housing below said compressor, said pump having two cooperating pumping members, one ofsaid members being stationary, said other member being connected with said-rotary container,

6. A motor-compressor unit for refrigerating systems, comprising a sealed housing forming an oil sump, a limited quantity ofoil disposed in said sump, an electric motor having a vertical arranged in said housing and having a hollow shaft andbeing disposed in the upper portion of said housing, and a compressor disposed in the 'lower portion of said housing, said compressor in-' cluding a stationary member having a suction duct and a compression duct, said compression duct. communicating with the interior of said housing, a check valve arranged between said compression duct and the interiorof said housing, animpeller firmly mounted on said shaft and anindependently rotatable container eccentrically surrounding said impeller and forming a pumping chamber together with said impeller, said suction duct and said compression duct being arranged to sequentially communicate with said chamber when said impeller is in operation,

- said container having ducts communicating with gether withsaid impeller, said container having' connecting said chamber with the hollowof said shaft and another duct for connecting said said sump to effect the formation of an oil'ring impeller is in operation.

'7LIA motor-compressor unit,in particular for refrigerating apparatus,- comprising a sealed housing forming an oil sump, a limited quantity ofoil disposed in said sump, an electric motor having a vertical shaft and being the upper portion of'said housing, and a'compressor disposed in the lower portion of said housing, said compressor including a stationary member having a suction duct and a compression duct, an impeller. mounted on said shaft, and a rotary container .eccentrically surrounding said impeller so as to form a pumping chamber to- I refrigerating apparatus, comprising. a a housing forming an oil sump, a limited quantity ofoil disposed in said sump, an electric motor having a vertical shaft and being disposed in the compressively acting on said chamber when said .housing.

10. A motor-compressor unit ofthe class deand a conduit system connecting said'pump' with the places to be lubricated in said upper portion a of said housing. v v

9. A motor-compressor unit of the class described, 7 comprising a pressure-tight housing forming a sump, a limited quantity of pumping liquid disposed in said sump, an electric motor shaft, animpeller mounted on said shaft, a ro- .tatable container eccentrically surrounding said impeller and forming a pumping chamber toduct means communicating with said sump to allow, when said impeller is in operation, the, formation of an annular body ofsaid liquid for alternately producing suction and compression in said chamber, said impeller having a duct for chamber with the interior of said housing, said ducts being arranged to sequentially icommunicate. with said hollow andthe interior of said housing during the rotationof said impeller, and two conduits for conveyingthe fluid to be compressed, one of said conduits being connected with the hollow of said shaft, and said other conduit being connected with the interior of'said scribed, comprising a pressure tight housing forming a sump, a limited quantity of' pumping.

liquid disposed in said sump, an'electric motor arranged in said housing and having a hollow shaft, an impeller mounted'on said shaft and having a peripheral recess, a container eccentric'ally surrounding said impeller and forming a pumping chamber togetherfwith said impeller,

said impellerhaving a projection limiting the peripheral length of said recess, a duct connecting one peripheral end ofsaid recess'wi-th 'said hollow shaft, and a. second duct opening into the other end ofvsaid recess, said container having apassage connecting its interior with r said sump to allow, when said impeller is in operation, the formation of an annular body of said pumping liquid for compressively acting on upper portion of saidhousing, and a compressor disposed in the lower portion of saidhousing,

said compressor including-a stationary member said chamber', tw o conduits for conveying the fluid to becompressed, one of said con .uits being connected with the hollow of said shaft, the

other conduit being in communication with'said second duct, and a check valve associated with said unit so as to control one of said ducts.

11 A motor-compressor unit of the class de-' scribed, comprising a pressure-tight housing forming a sump, a limited quantity of pumping liquid disposed in said sump, an electric motor arranged. in said housing and having a hollow shaft, an impeller mounted on said shaft and having a peripheral recess, a projection limitingthe peripheral length of said recess, a suction .duct connecting one peripheral end of said resaid impeller and forming a pumping chambertogether with the recessed peripheral portion of said impeller, said container having duct means communicating with said sump to allow, when said impeller is in operation, the formation of an annular body of said liquid for alternately producing suction and compression in said chamber, a suction conduit connected with the hollow of said shaft, and a pressure conduit connected with said housing.

12. A motor-compressor unit'of the class described, comprising a pressure-tight housing forming an oil sump, a limited quantity of oil disposed in said sump, a rigid support disposed in said housing, an electric motor mounted on said support, an impeller of a liquid-ring pump connected with said motor, a rotary container eccentrically surrounding said impeller and communicating with said sump to allow said oil to form a ring in said container when impelled by said impeller, a lubrication pump having a rotary pumping member associated with said container, and a stationary pumping member mounted on said support, stationary conduit means connecting said pump with said motor for supplying oil directly from said sump to the parts to be lubricated of said motor, and two conduits communicating with the interior of said liquid-ring pump and the interior of said housing, respectively, for conveying to and from said unit the fluid to be compressed.

13. A motor-compressor unit, in particular for refrigerating apparatus, comprising a sealed housing forming an oil sump, a limited quantity of oil disposed in said sump, an electric motor having a vertical shaft and being disposed in the upper portion of said housing, and a compressor having a stationary member having a suction duct and a compression duct and being disposed in the lower portion of said housing,

said compressor including an impeller mounted on said shaft, and a rotary container eccentrically surrounding said impeller and forming a pumping chamber together with said, impeller. said suction duct and said compression duct being arranged to sequentially communicate with said chamber, said container having oil es communicatingwith said sump to permit, when in operation, part of said 011 to enter into said container to allow the formation of an oil ring in said container compressively acting on said chamber, a rotary lubrication pump arranged in said housing below said compressor, said pump having two cooperating pumping members, one of said members being stationary, said other member being connected with said rotary container, an oil cooler arranged exteriorly of said housing, an oil conduit connecting said cooler with said pump, and another oil conduit connecting said cooler with the upper end of said vertical shaft.

RUDOLF HINTZE. 

